Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
Sci China Life Sci. 2020 Jun;63(6):886-897. doi: 10.1007/s11427-020-1679-1. Epub 2020 Mar 16.
Asgard is an archaeal superphylum that might hold the key to understand the origin of eukaryotes, but its diversity and ecological roles remain poorly understood. Here, we reconstructed 15 metagenomic-assembled genomes from coastal sediments covering most known Asgard archaea and a novel group, which is proposed as a new Asgard phylum named as the "Gerdarchaeota". Genomic analyses predict that Gerdarchaeota are facultative anaerobes in utilizing both organic and inorganic carbon. Unlike their closest relatives Heimdallarchaeota, Gerdarchaeota have genes encoding for cellulase and enzymes involved in the tetrahydromethanopterin-based Wood-Ljungdahl pathway. Transcriptomics showed that most of our identified Asgard archaea are capable of degrading organic matter, including peptides, amino acids and fatty acids, occupying ecological niches in different depths of layers of the sediments. Overall, this study broadens the diversity of the mysterious Asgard archaea and provides evidence for their ecological roles in coastal sediments.
古菌超门 Asgard 可能是理解真核生物起源的关键，但人们对其多样性和生态作用仍知之甚少。在这里，我们从覆盖大多数已知的 Asgard 古菌和一个新的古菌群的沿海沉积物中重建了 15 个宏基因组组装基因组，该古菌群被提议作为一个新的 Asgard 门，命名为“Gerdarchaeota”。基因组分析预测，Gerdarchaeota 是兼性厌氧菌，能够利用有机和无机碳。与它们最亲近的亲属 Heimdallarchaeota 不同，Gerdarchaeota 拥有编码纤维素酶和参与四氢甲烷蝶呤基 Wood-Ljungdahl 途径的酶的基因。转录组学表明，我们鉴定的大多数 Asgard 古菌都能够降解有机物质，包括肽、氨基酸和脂肪酸，占据了沉积物不同深度层的生态位。总的来说，这项研究拓宽了神秘的 Asgard 古菌的多样性，并为它们在沿海沉积物中的生态作用提供了证据。
